This research will study young adults, 18-22 years of age, who are at low or high risk for type 2 diabetes (also called NIDDM, non-insulin dependent diabetes mellitus, adult-onset diabetes). The proportion of the population that has type 2 diabetes has climbed steadily in this century. Native Americans are especially at risk, and now have some of the highest rates of diabetes in the world. We know that this rapid increase in rates of type 2 diabetes among all people must have something to do with lifestyle changes that have taken place in this century, and it appears that some people are at higher risk than others. We do not know exactly how lifestyle changes are bringing about the increase in diabetes.